Power supply apparatuses are essential for many electronic appliances such as personal computers, industrial computers, servers, communication products or network products. Normally, the power supply apparatus may provide stable electricity to the electronic appliance. In a case that the power supply apparatus has a breakdown, the electronic appliance is possibly damaged or the data stored in the electronic appliance is lost. For enhancing capacity and reliability of power supply, a redundant power supply system has been proposed. The redundant power supply system includes a plurality of separated power supply apparatuses, which are electrically connected to each other and contained in a system cabinet. During operation of the redundant power supply system, individual power supply apparatuses share responsibility for providing electricity to the electronic appliance. If one of the power supply apparatuses has a breakdown and fails to normally provide electricity, the others could continuously provide electricity to the loads.
Referring to FIG. 1, a schematic exploded view of a conventional power supply apparatus for use with a redundant power supply system is illustrated. The power supply apparatus 1 includes a casing 10, a fan 11 and a circuit board 12. Several electronic components 121 are mounted on the circuit board 12. The fan 11 is embedded into an opening at a side of the casing 10 to remove heat generated from the electronic components contained in the casing 10. During operation of the fan 11, the ambient air is inhaled into the space within the casing 10 in the direction indicated as the arrow. The inhaled air is then conducted to the electronic components 121 of the circuit board 12 to partially remove the heat generated from the electronic components 121. At the same time, a hot airflow is exhausted to the surroundings through the fan 11. Since the hot airflow is exhausted through the fan 11, the temperature of the airflow in the vicinity of the fan 11 is relatively large. Due to the elevated temperature, the fan 11 has shortened life and impaired operating performance or even generates noise during operation.
Since the fan 11 is mounted on one side of the casing 10, the direction of the airflow is predetermined according to the manufacturer's design. For complying with the system cabinet of the redundant power supply system, the fan 11 should be located at either the front side or the rear side of the power supply apparatus 1. Therefore, the layout flexibility of the power supply apparatus 1 is insufficient.
In views of the above-described disadvantages resulted from the conventional method, the applicant keeps on carving unflaggingly to develop a power supply apparatus for use with a redundant power supply system according to the present invention through wholehearted experience and research